A portion of a tunnel at a troubled nuclear site in Washington state collapsed on rail cars full of radioactive waste, prompting authorities to declare an emergency and evacuate workers.
Others at the U.S. Department of Energy’s Hanford Nuclear Reservation were initially told to shelter in place after ”soil has subsided” in a 20-foot, by 20-foot section of a tunnel. There were no workers inside the tunnel when it collapsed, the Associated Press reported.
Later Tuesday, the Energy Department said “The incident is moving from the emergency phase towards the recovery phase.”
There was no evidence that workers were exposed or radiation released into the air, according to the agency.
“The workforce has safely left the site, other than personnel essential to the recovery plan,” the statement said.
The incident occurred in an area of the sprawling complex where millions of gallons of plutonium and other nuclear waste from Cold War weapons production are stored, said Nickolas A. Bumpaous, an official with the UA Local Union 598 Plumbers & Steamfitters, which represents hundreds of Hanford workers.
The incident was discovered by workers during a “routine surveillance” of the area, the Hanford Emergency Operations Center said on its website. A remote device is being used to monitor for signs of any release of radiation, the center said.
The Hanford site, about 200 miles from Seattle, produced plutonium for U.S. nuclear weapons from World War II through the Cold War. The plant shuttered, and now a treatment facility is designed to process 56 million gallons of waste that is stored in 177 underground tanks prone to leaks.
Four years ago, Washington Governor Jay Inslee dragged the Hanford site into the spotlight after disclosing that six tanks holding radioactive waste at the complex were leaking, with one underground storage tank losing as much as 300 gallons of radioactive sludge a year. He said at the time that it could take years to start transferring sludge from the leaking tanks.
The Energy Department is in the midst of a nearly $17 billion clean up at the site, with work being conducted by the closely held Bechtel Corp.
“We need to understand whether there has been any environmental contamination resulting from the subsidence at these tunnels,” Washington Democratic Senator Maria Cantwell said in a statement.